CBSE 11TH CHEMISTRY - Online Test
Q1.
The general electronic configuration of ns2 exit in:
Answer : Option A
Explaination / Solution:
The general electronic configuration of ns2 exists in alkaline earth metals as their outer most electron enter the S orbital and they have only two electrons in their valence shell
Q2. Standard enthalpy of fusion or molar enthalpy of fusion is
Answer : Option B
Explaination / Solution:
The enthalpy change that accompanies melting of one mole of a solid substance in standard state is enthalpy of fusion.
Q3. Electronic configuration of an element is:
Answer : Option A
Explaination / Solution:
The electronic configuration of an atom, describes the arrangement of electrons in space around the nucleus. The electrons are distributed over different energy level. These energy levels are called the shell or orbits.
Q4. Consider the ground state of Cr atom (Z = 24). The numbers of electrons with the azimuthal quantum numbers, l = 1 and 2 are, respectively:
Answer : Option D
Explaination / Solution:
Azimuthal quantum number l = 1 is for p and l = 2 is for d.
Now Cr has configuration
Hence there are 12, p-electrons and 5, d-electrons
Q5. Carbon monoxide is poisonous to human beings because :
Answer : Option C
Explaination / Solution:
CO has more affinity to bind to Hb than oxygen. So it blocks the binding of oxygen to Hb causing deficiency of it and can lead to death.
Q6. Most of the s-block elements form dihydrogen compounds which are:
Answer : Option B
Explaination / Solution:
Ionic hydrides are formed when hydrogen molecule reacts with most s-block elements which are highly electropositive in nature.
In solid state, the ionic hydrides are crystalline, non-conducting and non-volatile.
However, in liquid state it conducts electricity. Ionic hydrides on electrolysis liberate hydrogen gas at the anode.
Q7. For , bond order is
Answer : Option C
Explaination / Solution:
Bond order is the number of chemical bonds between a pair of atoms. in diatomic nitrogen N≡N, Triple covalent bond is present in nitrogen so the bond order is 3;
Q8. Correct IUPAC name the following compound is
Answer : Option D
Explaination / Solution:
3,4- dimethylhexane will be correct iupac name as 6 membered carbon chain will be the main chain.
Q9. Molecular mass of a compound is the ------------- of atomic masses of elements present in a molecule .
Answer : Option B
Explaination / Solution:
Molecular mass is the sum of atomic masses of the elements present in a molecule.
For example ; Molecular mass of CO2 = atomic mass of one carbon atom & atomic mass of two oxygen atoms
=[ 12+2(16) ] u
= 44u.
Q10. Increase in kinetic energy can overcome intermolecular forces of attraction. How will the viscosity of liquid be affected by the increase in temperature?
Answer : Option D
Explaination / Solution:
Viscosity is inversely proportional to temperature., hence viscosity of the given liquid decreases with rise in temperature since, the liquid particles can move more freely as the friction between them become lesser.
